This Article 
 Bibliographic References 
 Add to: 
Interactive Ray Tracing for Volume Visualization
July-September 1999 (vol. 5 no. 3)
pp. 238-250

Abstract—We present a brute-force ray tracing system for interactive volume visualization. The system runs on a conventional (distributed) shared-memory multiprocessor machine. For each pixel we trace a ray through a volume to compute the color for that pixel. Although this method has high intrinsic computational cost, its simplicity and scalability make it ideal for large datasets on current high-end parallel systems. To gain efficiency several optimizations are used including a volume bricking scheme and a shallow data hierarchy. These optimizations are used in three separate visualization algorithms: isosurfacing of rectilinear data, isosurfacing of unstructured data, and maximum-intensity projection on rectilinear data. The system runs interactively (i.e., several frames per second) on an SGI Reality Monster. The graphics capabilities of the Reality Monster are used only for display of the final color image.

[1] S. Parker et al., "Interactive Ray Tracing for Isosurface Rendering," Proc. Visualization 98, CD-ROM, ACM Press, New York, Oct. 1998.
[2] S. Parker et al., "Interactive Ray Tracing," Symp. Interactive 3D Graphics, ACM Press, New York, 1999, pp. 119-126.
[3] J.T. Kajiya, “An Overview and Comparison of Rendering Methods,” A Consumer's and Developer's Guide to Image Synthesis, pp. 259-263, 1988.
[4] M. Levoy, “Display of Surfaces from Volume Data,” IEEE Computer Graphics and Applications, vol. 8, no. 3, pp. 29-37, 1988.
[5] P. Sabella,“A rendering algorithm for visualizing 3D scalar fields,” Computer Graphics, vol. 22, pp. 51-58, Aug. 1988.
[6] C. Upson and M. Keeler,“V-BUFFER: Visible volume rendering,” Computer Graphics, vol. 22, pp. 59-64, Aug. 1988.
[7] E. Reinhard, A.G. Chalmers, and F.W. Jansen, “Overview of Parallel Photo-Realistic Graphics,” Proc. Eurographics '98, 1998.
[8] A.F. Kaufman, Volume Visualization. IEEE CS Press, 1990.
[9] L.M. Sobierajski and A.E. Kaufman, “Volumetric Ray Tracing,” Proc. 1994 Symp. Volume Visualization, IEEE Computer Society Press, Los Alamitos, Calif., 1994, pp. 11-18.
[10] K.-L. Ma et al., "Parallel Volume Rendering Using Binary-Swap Compositing," IEEE Computer Graphics and Applications, vol. 14, no. 4, pp. 59-68, July 1994.
[11] M.J. Muuss, “RT and REMRT-Shared Memory Parallel and Network Distributed Ray-Tracing Programs,” USENIX: Proc. Fourth Computer Graphics Workshop, Oct. 1987.
[12] G. Vézina, P.A. Fletcher, and P.K. Robertson, "Volume Rendering on the MasPar MP-1," Proc. 1992 Workshop on Volume Visualization, Oct. 1992, pp. 3-8.
[13] P. Schröder and G. Stoll, “Data Parallel Volume Rendering as Line Drawing,” Proc. 1992 Workshop Volume Visualization, pp. 25-31, Boston, 19-20 Oct. 1992.
[14] M.J. Muuss, “Towards Real-Time Ray-Tracing of Combinatorial Solid Geometric Models,” Proc. BRL-CAD Symp., June 1995.
[15] S. Whitman, “A Survey of Parallel Algorithms for Graphics and Visualization,” Proc. High Performance Computing for Computer Graphics and Visualization, pp. 3-22, Swansea, 3-4 July 1995.
[16] B. Wyvill, G. Wyvill, C. McPheeters, “Data Structures for Soft Objects,” The Visual Computer, vol. 2, pp. 227-234, 1986.
[17] W.E. Lorensen and H.E. Cline, “Marching Cubes: A High Resolution 3D Surface Construction Algorithm,” Computer Graphics (SIGGRAPH '87 Proc.), vol. 21, pp. 163-169, 1987.
[18] C.-C. Lin and Y.-T. Ching, “An Efficient Volume-Rendering Algorithm with an Analytic Approach,” The Visual Computer, vol. 12, no. 10, pp. 515-526, 1996.
[19] S.R. Marschner and R.J. Lobb, "An Evaluation of Reconstruction Filters for Volume Rendering," Proc. Visualization '94, pp. 100-107, IEEE CS Press, Oct. 1994.
[20] M. Sramek, “Fast Surface Rendering from Raster Data by Voxel Traversal Using Chessboard Distance,” Proc. Visualization '94, pp. 188-195, Oct. 1994.
[21] G. Sakas, M. Grimm, and A. Savopoulos, “Optimized Maximum Intensity Projection (MIP),” Proc. Eurographics Rendering Workshop 1995, June 1995.
[22] R.A. Drebin, L. Carpenter, and P. Hanrahan, “Volume Rendering,” Computer Graphics (SIGGRAPH '88 Proc.), no. 22, pp. 65-74, 1988.
[23] D. Speray and S. Kennon, “Volume Probe: Interactive Data Exploration on Arbitrary Grids,” Computer Graphics, vol. 24, no. 5, pp. 5-12, 1990.
[24] J. Amanatides and A. Woo, “A Fast Voxel Traversal Algorithm for Ray Tracing,” Proc. Eurographics '87, 1987.
[25] A. Fujimoto, T. Takayu, and K. Iwata, "ARTS: Accelerated Ray-Tracing System," IEEE Computer Graphics and Applications, Vol. 6, No. 4, April 1986, pp. 16-26.
[26] J. Danskin and P. Hanrahan,“Fast algorithms for volume ray tracing,” 1992 Workshop Volume Visualization, pp. 91-98, Oct. 1992.
[27] M. Levoy, “Efficient Ray Tracing of Volume Data,” ACM Trans. Graphics, vol. 9, no. 3, pp. 245-261, July 1990.
[28] J. Wilhelms and A. Van Gelder, "Octree for Faster Isosurface Generation," ACM Computer Graphics, vol. 24, no. 5, pp. 57-62, Nov. 1990.
[29] J. Wilhelms and A. Van Gelder, "Octrees for Faster Isosurface Generation," ACM Trans. Graphics, vol. 11, no. 3, July 1992, pp. 201-227.
[30] J. Wilhelms, J. Challinger, N. Alper, S. Ramamoorthy, and A. Vaziri, “Direct Volume Rendering of Curvilinear Volumes,” Computer Graphics (Proc. 1990 ACM Workshop Volume Visualization), vol. 24, no. 2, pp. 41-48, 1990.
[31] M. Garrity, “Raytracing Irregular Volume,” Computer Graphics (Proc. 1990 ACM Workshop Volume Visualization), vol. 24, no. 2, pp. 35-40, 1990.
[32] C. Silva, J.S.B. Mitchell, and A.E. Kaufman, "Fast Rendering of Irregular Grids," in 1996 Symp. Volume Visualization, ACM Press, New York, pp. 15-22.
[33] C.E. Prakash and S. Manohar, “Volume Rendering of Unstructured Grids—A Voxelization Approach,” Computers&Graphics, vol. 19, no. 5, pp. 711-726, Sept. 1995.
[34] M.B. Cox and D. Ellsworth, "Application-Controlled Demand Paging for Out-of-Core Visualization," Proc. Visualization 97, ACM Press, New York, Oct. 1997, pp. 235-244.
[35] J. Arvo and D. Kirk, "A Survey of Ray Tracing Acceleration Techniques," An Introduction to Ray Tracing, A.S. Glassner, ed., Academic Press, San Diego, 1989.
[36] D. Jevans and B. Wyvill, “Adaptive Voxel Subdivision for Ray Tracing,” Proc. Graphics Interface '89, pp. 164-172, June 1989.
[37] K.S. Klimansezewski and T.W. Sederberg, "Faster Ray Tracing Using Adaptive Grids," IEEE Computer Graphics and Applications, vol. 17, no. 1, Jan./Feb. 1997, pp. 42-51.
[38] A. Globus, “Octree Optimization,” Technical Report RNR-90-011, NASA Ames Research Center, July 1990.
[39] G.M. Nielson and B. Hamann, The Asymptotic Decider: Removing the Ambiguity in Marching Cubes Proc. Visualization '91, pp. 83-91, 1991.
[40] Nat'l Library of Medicine (U.S.) Board of Regents, “Electronic Imaging: Report of the Board of Regents, U.S. Dept. of Health and Human Services, Public Health Service, Nat'l Inst. of Health,” NIH Publication 90-2197, 1990.
[41] B. Lorensen, “Marching Through the Visible Woman,”, 1997.
[42] Y. Livnat, H. Shen, and C.R. Johnson, "A Near Optimal Isosurface Extraction Algorithm Using the Span Space," IEEE Trans. Visualization and Computer Graphics, vol. 2, no. 1, Mar. 1996, pp. 73-84.
[43] M. Brady, K. Jung, H. Nguyen, and T. Nguyen, “Interactive Volume Navigation,” IEEE Trans. Visualization and Computer Graphics, vol. 4, no. 3, pp. 243-256, July-Sept. 1998.
[44] J. Schwarze, “Cubic and Quartic Roots,” Graphics Gems, A. Glassner, ed., pp. 404-407, San Diego, Calif.: Academic Press, 1990.

Index Terms:
Ray tracing, visualization, isosurface, maximum-intensity projection.
Steven Parker, Michael Parker, Yarden Livnat, Peter-Pike Sloan, Charles Hansen, Peter Shirley, "Interactive Ray Tracing for Volume Visualization," IEEE Transactions on Visualization and Computer Graphics, vol. 5, no. 3, pp. 238-250, July-Sept. 1999, doi:10.1109/2945.795215
Usage of this product signifies your acceptance of the Terms of Use.